Prior patents for collapsible funnels have been issued. Most of these inventions provide for collapsible funnels to be inserted and enclosed into liquid receptacles and to spring out when the closing cap is removed. Later improvements also included rods to push funnels into or pull them out of necks or filling spouts of various liquid receptacles such as automobile radiators, when not being used or when in operative position respectively.
U.S. Pat. No. 1,461,654 dated Jul. 10, 1922 to W. J. Haessler discloses a collapsible funnel with a rod vertically arranged within the funnel and inseparably attached to a screw cap. The limitation of the prior art is that the rod and the cap are in the way, since the rod is unmoveable, when the user pours a given liquid into the funnel, such an arrangement makes it difficult to use the device, causes spillage, accidental splashing and gets liquid onto the screw cap which the user wants to avoid.